java - 当用户选择今天之前的日期时，Android Java 显示错误消息

Question

下面是我的 Datepicker 代码，允许用户选择日期并使用所选日期更新 TextView 。当用户选择今天之前的日期时，如何使用错误消息更新 TextView ？

public void startCalender() {

    txtTrigger = (TextView) findViewById(R.id.calTrigger);
    final DatePickerDialog.OnDateSetListener date = new DatePickerDialog.OnDateSetListener() {
        @Override
        public void onDateSet(DatePicker view, int year, int month, int day) {
            myCalendar.set(Calendar.DAY_OF_MONTH, day);
            myCalendar.set(Calendar.MONTH, month);
            myCalendar.set(Calendar.YEAR, year);
            updateLabel();
        }
    };
    txtTrigger.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            new DatePickerDialog(DisplayCeeAct.this, date,
                    myCalendar.get(Calendar.YEAR), myCalendar.get(Calendar.MONTH),
                    myCalendar.get(Calendar.DAY_OF_MONTH)).show();
        }
    });
}

private void updateLabel() {
    String no = "<font color='red'>NO</font>.";
    String myFormat = "dd/MM/yy";
    SimpleDateFormat sdf = new SimpleDateFormat(myFormat, Locale.getDefault());

    if (myCalendar.after(myCalendar.getTime())){
        txtTrigger.setText(sdf.format(myCalendar.getTime()));
    }
    else {
        txtTrigger.setText(Html.fromHtml(no), TextView.BufferType.SPANNABLE);
    }
}

Answer 1

这条线似乎崩溃了:

txtTrigger.setText(Html.fromHtml(no), TextView.BufferType.SPANNABLE);

更好的方法是:

txtTrigger.setText("NO");
txtTrigger.setTextColor(Color.RED);